Welcome to ERDDA.se

This site presents the comparative data collection efforts undertaken by professor This email address is being protected from spambots. You need JavaScript enabled to view it. at Södertörn University, Stockholm, and his colleagues around the world. The webmaster is This email address is being protected from spambots. You need JavaScript enabled to view it..

The main sponsor of the Data Archive has been Riksbankens jubileumsfond (In2007-0149:1-E and P2007-0370:1-E). Since 2011 the data archive has been sponsored by Östersjöstiftelsen (dnr A050-10).

Please select one of the projects to enter.


The Governments in Europe Data Archive [ongoing project]

The Governments in Europe project connects ten senior scholars in ten Baltic and East Central Europe countries with Södertörn University in Sweden for the purpose of conducting cutting edge comparative research on the formation and stability of national governments. In particular, the project examines two aspects that have not yet been the subject of scholarly inquiry within the region: coalition governance and specific reasons for cabinet termination.

The European Representative Democracy Data Archive - Release 3.0 - Published Feb 12, 2014

We are now able to present a new release (3.0) of the data set on European cabinets, parliaments and political parties. The data are collected for the study of some of the most important events in representative democracy: the formation and termination of governments. In addition, inspired by Peter Mair’s (1998: 86) statement in A New Handbook of Political Science (Oxford University Press) that “it must surely remain a priority for comparative research to stimulate the collection of systematically comparable data” we have resisted the temptation to code what we first found and instead double-checked multiple sources against each other to establish the best possible coding. Release 2.0 contained new estimates for v007e (code for date out), v700e (total cabinet volatility), v701e (average cabinet volatility) and  v708e (cabinet electoral performance). Release 3.0 includes a few corrections, a new variable, majority coalition, v326e_add, and more data on the  end dates of the cabinets that formed before or on December 31 2010 (up through December 2013).

May 15, 2012. A new dissertation. For a long period of time the same group of parties dominated Western parliamentary democracies. In the famous words of Lipset and Rokkan (1967) the party systems of Western Europe had frozen. However, beginning in the 1970s the consolidated party systems started to melt. Nowadays, new political parties are an important part of parliamentary democracy. In accordance with this development we present a new dataset regarding new party entrances in Western Europe.

The Comparative Parliamentary Democracy Data Archive - New data added March 2012

The CPD program is devoted to the comprehensive study of West European cabinets and informed by and has contributed greatly to coalition research. The various volumes produced by the CPD program describe every governing coalition, the parliamentary seat distribution, and the institutional rules parliaments operated under from the beginning of the post-World War II to 1999.

The Madisonian Turn - Nordic Politics Data Archive

This section presents information concerning Nordic politics, such as interviews with Nordic politicians and other useful information on Nordic politics translated to English. This data provides (1) information on the 2011 volume The Madisonian Turn, (2) a recently completed research project about Swedish constitutional reforms and (3) a chronological account of how the Swedish electoral law has changed since World War II.